I tried to import some MD files into PolarDB vector database. Some files hit errors like follow: Failed file: monthly_2021_07_05.md Log file: import_with_errors.log Error context: 2025-10-28 17:23:07,807 - INFO - Vector generated successfully with variant 1 in 1.37s 2025-10-28 17:23:10,157 - ERROR - Error executing SQL '/polar4ai/SELECT * FROM predict(model _polar4ai_text2vec, SELECT 'alter table有很多种，这里是最复杂的重建表的逻辑。这种...': 2003 (HY000): Execute sql failed in ai db 2025-10-28 17:23:10,158 - ERROR - Exception type: DatabaseError 2025-10-28 17:23:11,435 - ERROR - Error executing SQL '/polar4ai/SELECT predict_text2vec('alter table有很多种，这里是最复杂的重建表的逻辑。这种情况下DDL log既是redo，也是undo。 执行阶段首先...': 2003 (HY000): Execute sql failed in ai db 2025-10-28 17:23:11,436 - ERROR - Exception type: DatabaseError
Failed file: monthly_2021_07_05.md Log file: import_with_errors.log Error context: 2025-10-28 17:23:10,158 - ERROR - Exception type: DatabaseError 2025-10-28 17:23:11,435 - ERROR - Error executing SQL '/polar4ai/SELECT predict_text2vec('alter table有很多种，这里是最复杂的重建表的逻辑。这种情况下DDL log既是redo，也是undo。 执行阶段首先...': 2003 (HY000): Execute sql failed in ai db 2025-10-28 17:23:11,436 - ERROR - Exception type: DatabaseError 2025-10-28 17:23:12,483 - ERROR - Error executing SQL 'SELECT text2vec('alter table有很多种，这里是最复杂的重建表的逻辑。这种情况下DDL log既是redo，也是undo。 执行阶段首先是建立了两个分区表，一开始走了creat...': 1305 (42000): FUNCTION polar4aidb.text2vec does not exist 2025-10-28 17:23:12,484 - ERROR - Exception type: ProgrammingError
Failed file: monthly_2021_07_05.md Log file: import_with_errors.log Error context: 2025-10-28 17:23:11,436 - ERROR - Exception type: DatabaseError 2025-10-28 17:23:12,483 - ERROR - Error executing SQL 'SELECT text2vec('alter table有很多种，这里是最复杂的重建表的逻辑。这种情况下DDL log既是redo，也是undo。 执行阶段首先是建立了两个分区表，一开始走了creat...': 1305 (42000): FUNCTION polar4aidb.text2vec does not exist 2025-10-28 17:23:12,484 - ERROR - Exception type: ProgrammingError 2025-10-28 17:23:12,484 - ERROR - Failed to generate vector for text: alter table有很多种，这里是最复杂的重建表的逻辑。这种情况下DDL log既是redo，也... 2025-10-28 17:23:12,484 - ERROR - All query variants failed
But when I try to re-import the same set of files again (no changes to file content at all). The import will then success. Why?
